Review of Forma 28

The Forma 28 is equipped with a fractional rig. A fractional rig has smaller headsails which make tacking easier, which is an advantage for cruisers and racers, of course. The downside is that having the wind from behind often requires a gennaker or a spinnaker for optimal speed.

Unknown keel type

The keel is made of iron. Many people prefer lead keel in favour of iron. The main argument is that lead is much heavier than iron and a lead keel can therefore be made smaller which again result in less wet surface, i.e. less drag. In fact iron is quite heavy, just 30% less heavy than lead, so the advantage of a lead keel is often overstated.

The boat can enter even shallow marinas as the draft is just about 1.45 - 1.55 meter (4.76 - 5.06 ft) dependent on the load. See immersion rate below.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Forma 28 is 1.93, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 6.4 knots. The term "Theoretical Maximum Hull Speed" is widely used even though a boat can sail faster. The term shall be interpreted as above the theoretical speed a great additional power is necessary for a small gain in speed.

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Forma 28 is about 124 kg/cm, alternatively 698 lbs/inch.
Meaning: if you load 124 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 698 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Forma 28 is 21.4.

Comparing this ratio with similar sailboats show that it is more comfortable than 50% of all similar sailboat designs. This is an average comfort value!

What is L/B (Length Beam Ratio)?

The l/b ratio for Forma 28 is 3.15.

Compared with other similar sailboats it is slimmer than 62% of all other designs. It seems that the designer has chosen a slightly more speedy hull design.

What is a Ballast Ratio?

The ballast ratio for Forma 28 is 50%.

This ballast ratio shows a righting moment that is higher than 90% of all similar sailboat designs. A righting moment (ability to resist heeling) significantly above average.

What is Displacement Length Ratio?

The DL-ratio for Forma 28 is 237 which categorizes this boat among 'light crusers & offshore racers'.

54% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.

What is SA/D (Sail Area Displacement ratio)?

The SA/D for Forma 28 with ISO 8666 reference sail is 15.1, with a 135% genua the SA/D is 17.5.

The SA/D ratio indicates that it is faster than 38% of all similar sailboat designs in light wind.

The Forma 28 has more rig than 38% of all similar sailboats, which indicates that the boat is slightly underrigged.

What is Relative Speed Performance?

The Relative Speed Performance for Forma 28 is 42

The relative speed performance is 42 which means that a it is faster than 42% of all similar sailboat designs.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 21m² (226 ft²).
Based on this, your favourite maritime shop can tell you the quantity you need.

Note: If you use a paint roller you will need more paint than if you use a paintbrush.

Dimensions of sail for fractional rig.

Are your sails worn out? You might find your next sail here: Sails for Sale

If you need to renew parts of your running rig and is not quite sure of the dimensions, you may find the estimates computed below useful.

This section is reserved boat owner's modifications, improvements, etc. Here you might find (or contribute with) inspiration for your boat.

Do you have changes/improvements you would like to share? Upload a photo and describe what you have done.

We are always looking for new photos. If you can contribute with photos for Forma 28 it would be a great help.

If you have any comments to the review, improvement suggestions, or the like, feel free to contact us. Criticism helps us to improve.

[Ref 1]: ISO 8666 Small craft — Principal data.
[Ref 3]: ISO 12215-5 Small craft — Hull construction and scantlings.